Effect of indomethacin on the bone marrow and immune system of the mouse.

Bone marrow cellularity, hematopoietic progenitor cells and immune alterations were evaluated in mice following short term adult exposures to non-ulcerogenic levels of indomethacin. Body and organ weights showed no significant changes with the exception of the spleen where a dose dependent weight increase was noted. Bone marrow cellularity and pleuripotent hemopoietic stem cells (CFU-S) were unaltered while granulocyte-macrophage progenitors (CFU-GM) and splenic erythropoiesis were increased. Indomethacin exposure caused increased macrophage function as evidenced by enhanced phagocytosis. Lymphoproliferative response of splenocytes to T-cell mitogens was depressed while B-cell mitogenic response was not affected. These results indicate that indomethacin affects selective components of the immune and hemopoietic cells at dose levels that cause no other significant pathological alterations.